Treatment of artificial silks



Patented June 3,

UNITED STATES,

anus cmvnr, or mean-Amer, swn-znamnn TREATMENT OF ARTIFICIAL SILKS Io Drawing. Application flledlay 27, 1927, Serial No. 194,859, and in Germany September 17, 1926. 7 p

This invention relates to processes for weighting artificialsilks.

As is known, the weighting of artificial silks presents Very considerable difliculties, owing to the fact that artificial fibres of cellulose or cellulose derivatives are very sensitive to the action of weighting agents and in manycases to the'action'of water. The many passages of the hanks or fabrics through a series of 10 baths containing separately the individual weighting agents, as is customary in natural silk vweighting processes and-through the intermediate 'washing or neutralizing baths,

which are necessary between the actual weighting baths, are particularly unfavorable for artificial In the case of artificial silks made from cellulose esters, apart from the injury to the fibres, a saponifica-- tion of the cellulose esters often occurs, by which the silk suffers and frequently becomes useless. The aim of artificial silk weighting must therefore be to effect the weighting in as few baths as possible.

- I have now found that very successful weighting of artificial silks may be obtained by employing two or more weighting agents in one bath or by employing successive weighting baths (impregnating and precipi tating baths) without intermediate washing or neutralizing, the fibre and/or at least one of the baths having added or applied thereto a substance adapted to hinder premature precipitation, i. e. precipitation either in the bath or at the surface of the fibre.

Such substances may be mineral or organic acids, acid salts or salts having an acid reaction or protective colloids such as glue, gelatine, albumen or the like. If desired the substance used to hinder premature. precipitation may itself be a weighting substance. Thus .for example aluminum sulphate has a very pronounced acid reaction and may act 4 at the same time as a weighting agent.

When employing two or more weighting agentsin one bath according to the present invention, for example metal compounds (especially compounds of tin and zinc) and salts, e. g. phosphates, sulphates, silicates and the likeor acids such as phosphoric acid and also if desired tanning substances, the bath or two or more of such baths may be made up with-an acid, an acid salt or protective colloid or other agent adapted to hinder precipitation or wlth a mixture of such agents. The goods, may then be passed directly through the bath or two or more of such baths, or if desired an acid, acid salt or protective colloid or other agentadapted to hinder premature precipitation or a mixture thereof may also be applied to the goods themselves prior to passage through the bath or baths.

Again whenemployin successive weightmg aths (for example baths of tin or zinc compounds and of salts such as phosphates, sulphates, for instance ofalumina, or silicates, or of acids, for'example phosphoric acid) one or more of the said agents adapted to hinder precipitation may be applied to the goods or to at least one of the baths or both to the goods and at least oneofthe baths and the goods passed successively through the baths withoutintermediate washing or neutralizing.

By means of the invention the weighting 7 of artificial silks can beeifected by passing through only a comparatively small number' of baths, neutralizing and washing being eliminated, or even through a single bath only, and further the hanks, fabrics or other goods need only remain in the baths a very short time to obtain the required weighting.

In order to obtain a better fixation of the weighting agents and in certain cases in'orderto remove excess of acid, the materials after weighting and preferably after squeezing may be treated in a bath having an alkaline reaction, for example a solution of ammonium carbonate, to which if desireddyestufi's which contain tanning substances, such as haematein, may be added. The invention is applicable to the weighting of all artificial silks made from cellulose or cellulose derivatives, for example acetyl e5 cellulose silks,'viscose silks, Chardonnet silks and cuprammonium silks.

The following examples may be given in illustration of the invention, it being under} stood that they are in no way limitative and i can varied widely without departing from the spirit of the invention.

. i Example 1 ,5 An acetyl cellulose fabric woven .in the piece is passed through a finishing machine in which it passes first through a bath of litres of a aqueous albumen solution contaming 50 grams of ammonium carbonate. The 10 travelling fabric is squeezed out on the same machine and passes on into a second bath composed of a 4 per cent tin chloride solu ,tion containin 10'per cent phosphoric acid r litre. It'is dried and dyed withdirect dyestuffs. I Example? Acetyl cellulose artificial silk in any form 7 is soaked in a 5% solution of aluminum go acetate in the container of a centrifuge. The solution is run off and the goods centrifuged after which a solution containing 4% of tin chloride and 10% phosphoric acid is introduced. The goods may then again be centrifuged, treated with ammonium carbonate direct dyestufis. I

Example 3 10 litres of the weighing bath contain 200 grams zinc chloride. 100 grams sulphate of aluminium. 400 grams anhydrous tin chloride.

acetyl cellulose artificial silk, e. g. a crepe de chine fabric, is led in full width through a 1% aqueous solution of phos horic acid containing 12 grms. of glue per itre. The fabric is then carried directly through four tin chloride baths containing tin tetrachloride solution of B. strength and is thereafter ueezed and led first into a 10% monosodium phosphate bath. After the alkaline phosphate bath the fabric is hydro-extracted and may if desired be finally treated in a waterglass solution of 1 B. containing 1 gm. of

soap per litre.

Example 5 An artificial silk fabric is passed on a finishing machine through a 10 litre bath containing 400 grms. of zinc chloride and 100 grms. 'of formic acid. The fabric is then passed directly without washing through a 68% aqueous solution of monosodium phosphate. The artificial silk may then be squeezed, passed through a 5% solution of ammonium carbonate and dried.

' taining soap at 40 C.

solutlon and dried and if desired dyed with A fabric consisting wholly or partly of.

p osphate bath and then into a 6% disodium Example 6' -Acety'l'cellulose artificial silk in the form of hanks is immersed for a short time in a 1% solution of monochloracetic acid. The treated hanks are brought into a bath containing tin tetrachloride of 35 B6. and are then stretched and allowed to remain in the'air for a short time.- The procedure ma be repeated if desired. The hanks are we centrifu ed and entered for a short time into a 15% so ution of monosidum phosphate. They are s ueezed or hydro-extracted and if desired a er a short washing may be given a final treatment in a 1% solution of waterglass con- Goods of acetyl cellulose or the like weighted according to theinvention are increased in volume considerably and have a much increased afiinity for direct dyeing sulphonated dyestufi's, which ordinarily dye acetyl cellulose little or not at all. Owing to the relatively short duration of treatment in the baths their strength is substantially unimpaired.

Owing to the omission of intermediate washing 'or neutralization, diluted solutions of the weighing agents or of transformation products thereof resulting from neutralization are not obtained and in consequence the special installations and considerable expense usually entailed in the recovery of such agents or products are avoided.

An additional advantage accrues when a treatment of the goods with an' acid substance is carried out prior to the weighting, it being found that a more intensive and more uniform absorption of the weighting agents is brought about and the duration of the whole weig ting process is considerably reduced.

What I claim and desire to secure by Letters Patent is i 1. Process for weighting artificial silks, comprising treating them with a plurality of weighting agents without intermediate washing or neutralization, at least one substance being employed which is adapted to hinder premature precipitation.

2. Process for weighting acetyl cellulose artificial sllks comprising treating them with a plurality of weighing agents without intermediate washing or neutralization, at least one substance being employed which is adapted to hinder premature precipitation.

3. Process for weighting artificial silks, comprising treating them with a lurality of weighting agents in one bath, whlch contains at least one substance adapted to hinger premature precipitation.

4. Process for weighting artificial silks, comprising treating them with a plurality of weighting agents in one bath, which contains a substance having an acid reaction to hinder premature precipitation.

'5. Process for weighting artificial silks comprising treating them with a plurality of weighting agents inone bath, in the presence of a protective colloid and a substance having an acid reaction to hinder premature precipi tation. I

6. Process for weighting artificial silks,

comprising treating them with a plurality of weighting agents in one bath, which contains 1 an acid to hinder premature precipitation. 7. Process for weighting artificial silks, comprising treating them with a substance having an acid reaction and then with a plu rality of weighting agents in one bath, which contains a substance having an acid reaction to hinder premature precipitation.

8. Process for weighting artificial silks, comprising treating them with an acid and then with a'plurality of weighting agents Y in one bath, which contains an acid to hinder premature precipitation. I

'9. Process for weighting artificial silks, comprising treating them with a plurality of weighting agents in one bath, which contains a substance having an acid reaction to hinder premature precipitation, and there after treating with an alkaline solution.

10. Process 'for weighting artificial silks, comprising treating them with a plurality of weighting agents in one bath, which contains a substance having an acid reaction to. hinder premature precipitation, and thereafter treating with ammonium carbonate so-' lution.

11. Process for weighting artificial silks, comprisingtreating them with a plurality of weighting agents in one bath, which contains an acid to hinder premature precipitation and thereafter treating with an alkaline solution. I

l2.-'Process for weighting artificial silks, comprising treating them with an acid and then with a plurality of weighting agents in one bath, which contains an acid-to hinder premature precipitation and thereaftertreatin g with an alkaline solution.

'13-. Process for weighting acetyl cellulose artificial silks comprising treating them with a plurality of weighting agents in one bath, which contains at least one substance adapted to hinder premature precipitation.

14. Process for weighting acetyl cellulose artificial silks. comprising treating them with a plurality of weighting agents in one bath,- which contains an acid. to hinder permature 15. Process for weighting acetyl cellulose artificial silks, comprising treating them with an acid and then with a plurality ofweighting 'agents in one bath, which contains an acid to hinder premature precipitation.

16. Process for weighting acetyl cellulose artificial silks. comprising treating them with a plurality of weighting agents in one bath, which contains a substance having an acid reaction to hinder premature precipitation, and

thereafter treating with an alkaline solution. 1 7. Process for weighting acetyl cellulose art1ficial-"silks, comprising treating them with a plurality of weighting agents in one bath, whichcontains a substance having an acid reactionto hinder premature precipitation and thereafter treating with ammoniin the presence of a protective colloid and a 1 substance having an acid reaction to hinder premature precipitation.

, In testimony whereof I have hereunto subscribed my name.

RENE CLAVEL. 

